Single use cameras are commonly sold preloaded with a cartridge of film. In order to reduce complexity and costs, a rewind mechanism is omitted from the camera. Instead, the film is prewound and during use is advanced back into the film canister. A number of approaches have been followed in loading and prewinding film cartridges for single use cameras. In some approaches, such as one taught in U.S. Pat. No. 4,972,649; film is prewound into a roll outside the camera body and then loaded. A shortcoming of these approaches is that the film roll must be handled after it is formed. This presents a risk of film damage and may add complexity to necessary equipment. In some other approaches, also taught in U.S. Pat. No. 4,972,649; the cartridge is loaded, the camera is light-tightly closed, and the film is then prewound. In still other approaches, such as taught by U.S. Pat. No. 5,311,231; the cartridge is loaded and then the rear opening of the camera body is closed and the film is prewound through a bottom opening, which is later sealed. The latter two approaches have the shortcoming that film guiding is provided primarily by the camera body, rather than loading apparatus. This places constraints on the camera body in terms of required tolerances and the like and may, in addition, slow throughput speeds. Still another approach is taught by Japanese Kokai 6-295022, European Patent Application No. 0743546-A, and Japanese Kokai 8-171180. In this approach, the film is wound onto a second spool, rather than being wound into a film roll. The back of the camera is not mandatory for guiding the film, since the second spool tends to restrain the film.
It is known to use vacuum and/or compressed gas to direct and wind webs. U.S. Pat. No. 4,228,579 teaches the use of a vacuum mandrel for winding a film roll from bulk outside a cassette. Vacuum through slots in the mandrel is used to cinch protective tape (tape backed film). After the roll is formed it is loaded in the cassette and compressed air is used to drive the film off the mandrel. The film roll unfurls against the walls of the housing. U.S. Pat. No. 4,520,970 teaches a tape drive having a take-up hub with vacuum ports. A air jet is disposed to drive the tape toward the take-up hub. U.S. Pat. Nos. 4,794,475 and 3,795,371 teach other tape drives having air jets. U.S. Pat. No. 3,527,424 teaches a winding apparatus in which a sheet of metal or other material is wound onto a vacuum mandrel. Jets of pressurized fluid drive the sheet material toward the mandrel.
U.S. Pat. No. 2,781,983 and U.S. Pat. No. 4,418,874 teach web winding apparatus in which vibration is used to reduce friction during scroll formation.
Japanese Kokai 9-43777A, filed Jul. 28, 1995; and Japanese Kokai 9-43778A, filed Jul. 28, 1995 disclose methods for prewinding film from a cartridge within a fixture, using compressed air. The fill roll and cartridge are then transferred to a single use camera.
It would thus be desirable to provide camera assembly methods and apparatus and resulting cameras, in which a spoolless film roll is wound, from a cartridge, in the frame of a camera using compressed gas.